geography support

[628426]

Hi there, I have put geography support into the system based on Postgis add-on for Postgres.

• Database level has been completely updated to use the correct ST_Transform and SRID for either GeoJSON or Text, and custom spatial index type when searchable.

SDK has the

• FieldCard to add the field

• custom options for eitherGeoJSON or Text format (just for values, its all stored as geography type in the db) and the SRID

• a leaflet viewer (again in the SDK) just so it can be visualised

To make it as useful as the other parts of the system it needs:

• PcFieldGeography

I tried to copy PcFieldTextarea but it was beyond me

• Extending EQL to support ST_Contains/Intersects so it can be joined on

This was beyond me as wel

• It probably needs a WebVella.TagHelper?

I am not sure how all that fits together or what the design intention is with TagHelpers...

I have committed it to my fork in the hope someone can pick it up and get the rest of it over the line quickly. I am not going to do a pull request because its incomplete.